Falkland Is SG3 6d Green on a 1896 registered envelope to Germany RARE

1896 registered envelope to Germany bearing 1878 6d blue-green paying 4d postage and 2d registration tied by NO 14 CDS (another strike at base) and crown/ REGISTERED marking.  London transit on front Altona arrival on the reverse which also bears partial Port Stanley Agency/ Hamburg cachet.  Creasing towards base.  SG 3